Investigators are learning more about a blast outside a Palm Springs fertility clinic that killed the suspect and injured four people.

“Make no mistake: This is an intentional act of terrorism,” Akil Davis, the head of the FBI’s Los Angeles field office, told an evening news conference.

Law enforcement sources told CBS that the Bartkus, the suspect, is a resident of Twentynine Palms, home to a large marine base about an hour away from Palm Springs.